Risk of Initiating Antiarrhythmic Drug Therapy for Atrial Fibrillation in Patients Admitted to a University Hospital

Background: The risks of antiarrhythmic therapy are in-creasingly recognized, but the risks associated wi th the initiation of antiarrhythmic therapy in patients hospital-ized for atrial f ibri l lation are poorly defined. Objective: To determine the incidence, t ime course, and predictors of adverse cardiac events that require interven-t ion during initiation of antiarrhythmic drug therapy for atrial f ibri l lat ion. Design: Retrospective chart review. Setting: University hospital. Participants: 417 consecutive patients who underwent a total of 597 drug trials during a total of 550 hospitaliza-tions for atrial f ibri l lat ion. Intervention: Initiation of therapy wi th antiarrhythmic drugs: procainamide (189 trials), quinidine (179 trials), di